Witnesses

Bukhari :: Book 3 :: Volume 48 :: Hadith 832

Narrated Ibn 'Umar:

Allah's Apostle called me to present myself in front of him or
the eve of the battle of Uhud, while I was fourteen years of age at
that time, and he did not allow me to take part in that battle, but
he called me in front of him on the eve of the battle of the Trench
when I was fifteen years old, and he allowed me (to join the
battle)." Nafi' said, "I went to 'Umar bin 'Abdul Aziz who was
Caliph at that time and related the above narration to him, He
said, "This age (fifteen) is the limit between childhood and
manhood," and wrote to his governors to give salaries to those who
reached the age of fifteen.